This invention relates to structures for storing and feeding of various materials and, more particularly, to a hopper device for storing and feeding coarse and/or granulated material such as sawdust, wood chips, nut shells, corn cobs and the like at a controlled rate without packing or clogging and without constant manual attention.
It is common to burn granulated, otherwise waste material such as sawdust, wood chips, nut shells, corn cobs and the like for various energy producing functions such as heating. With a furnance or incinerator which burns such materials, it is necessary to store and feed such materials at a controlled rate so that proper combustion will continue. In the past, several problems have occurred which make the storing and feeding of such materials difficult, time-consuming and/or expensive.
First, the nature of the materials to be stored and fed as well as the requirements for such storage and feeding, often cause congestion at the outlet of the storing or feeding device. More specifically, with irregularly shaped, granulated and/or coarse materials such as nut shells, wood chips or corn cobs, clogging and jamming often occurs at the restricted outlet end of a hopper or other storage container. This has typically required the nearly constant attention of an operator which increases both the cost and difficulty in the feeding operation.
A second problem is that of continued, controlled feeding in outside areas in subfreezing temperatures. Since many incinerators or furnaces are fed from material stored outside, a common occurrence is the freezing in the storage hopper of moist or wet materials such as green or fresh sawdust, wood chips or the like. Prior known storage and feeding devices which may have included large blades or a stationary auger within a hopper were difficult or impossible to operate with frozen materials in the hopper since the blade or auger could not be moved to produce the desired, controlled feeding.
Other problems encountered with the use of storage and feeding devices for furnaces, boilers and the like included an inability to obtain access to the operative parts of a storage and feeding mechanism. Also, proper control over the desired feed rate from the storage and feeding device was often difficult.
The present invention was devised in recognition of and as a solution for the above and other problems encountered in the storage and direct or indirect feeding of otherwise waste materials intended for burning in furnaces, boilers and the like.